Thermo-magnetic cycle apparatus

ABSTRACT

A vehicle air-conditioner has a magneto-caloric effect type heat pump apparatus (MHP apparatus). MHP apparatus has a magneto-caloric element (MCE element) which generates heat dissipation and heat absorption in response to strength change of an external magnetic field. The MCE element can demonstrate high performance when an element temperature is in a highly efficient temperature zone. A controller has an initial control part which adjusts the element temperature so that the element temperature approaches to the highly efficient temperature zone when the MHP apparatus is in an initial state in which the temperature is out of the highly efficient temperature zone. Thereby, starting of MHP apparatus is promoted. The initial control part may activate an auxiliary apparatus. The auxiliary apparatus heats or cools a part or all of the MCE elements.

CROSS REFERENCE TO RELATED APPLICATION

This application is based on Japanese Patent Application No. 2013-89540 filed on Apr. 22, 2013, the disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a thermo-magnetic cycle apparatus using magneto-caloric effect of magnetic material. The thermo-magnetic cycle apparatus may be used as a magneto-caloric effect type heat pump apparatus.

BACKGROUND Patent Literature

-   PLT1: JP2012-255642A -   PLT2: US Patent Application Publication 2011/0173993A -   PLT3: JP2012-229831A

PLT1, PLT2, and PLT3 disclose a magneto-caloric effect type heat pump apparatus which is one embodiment of the thermo-magnetic cycle apparatus. The thermo-magnetic cycle apparatus uses temperature characteristics of a magnetic substance. PLT1, PLT2, and PLT3 propose an arrangement in which a plurality of elements is arranged in series between a high temperature end and a low temperature end.

PLT1 proposes a structure having a channel which bypasses a part of the elements. PLT2 proposes a structure having a starter element for providing an initial temperature gradient in a starting stage after starting an apparatus. PLT3 proposes a device which has an auxiliary heat source.

SUMMARY

The technique disclosed in PLT1 only uses a part of the magneto-caloric elements. Therefore, an output may be reduced. The technique disclosed in PLT2 disposes an element for starting the apparatus, therefore, an amount of the element for operation in regular stage has to be decreased. Therefore, an output may be reduced. The technique disclosed in PLT3 supplies thermal energy from an auxiliary heat source also at the time of regular steady operation. Therefore, excessive thermal energy may be supplied. In addition, effectiveness as the whole system may be lowered by the energy, such as electric power, consumed by the auxiliary heat source. It such view points, it is demanded to improve the thermo-magnetic cycle apparatus.

It is an object of the present disclosure to provide a thermo-magnetic cycle apparatus which is capable of reaching to a regular operating temperature from an initial temperature in short time.

It is another object of the present disclosure to provide a thermo-magnetic cycle apparatus which is capable of reaching to a regular operating temperature from an initial temperature in short time, and providing high effectiveness of energy at a regular operating temperature.

It is another object of the present disclosure to provide a thermo-magnetic cycle apparatus which is capable of starting operation from a wide temperature range without lowering performance at a regular operation.

The present disclosure employs the following technical means, in order to attain the above-mentioned object.

According to the disclosure, a thermo-magnetic cycle apparatus is provided. The apparatus comprises a magneto-caloric element which generates heat dissipation and heat absorption in response to strength change of an external magnetic field. The apparatus comprises a magnetic field modulating device which modulates an external magnetic field applied to the magneto-caloric element, and a heat transporting device which flows heat transport medium for performing heat exchange with the magneto-caloric element so that a high temperature end and a low temperature end are generated on the magneto-caloric element. The apparatus also comprises a controller which controls the magnetic field modulating device and the heat transporting device. The magneto-caloric element demonstrates high performance when an element temperature of the magneto-caloric element is in a highly efficient temperature zone. The controller comprises an initial control part which adjusts the element temperature of the magneto-caloric element so that the element temperature approaches to the highly efficient temperature zone when the magneto-caloric element is in an initial state in which the element temperature is out of the highly efficient temperature zone. The controller also comprises a regular control part which controls the magnetic field modulating device and the heat transporting device after adjustment of the element temperature by the initial control part is performed.

According to this disclosure, regular operation of the magneto-caloric element using the magnetic field modulating device and the heat transporting device is provided by the regular control part. In advance of regular operation performed by the regular control part, the initial control part adjusts the element temperature of the magneto-caloric element. In the initial state in which the element temperature is out of the highly efficient temperature zone, the initial control part adjusts the element temperature toward the highly efficient temperature zone. Accordingly, the temperature control by the initial control part is provided only in the initial state. Therefore, it is possible to eliminate adverse effect by the initial control part when the apparatus is in the regular operation.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings:

FIG. 1 is a block diagram of a magneto-caloric effect type heat pump apparatus (hereinafter MHP apparatus) according to a first embodiment;

FIG. 2 is a cross-sectional view of the MHP apparatus according to the first embodiment;

FIG. 3 is a cross-sectional view of the MHP apparatus according to the first embodiment;

FIG. 4 is a graph showing temperature characteristics according to the first embodiment;

FIG. 5 is a graph showing temperature characteristics according to the first embodiment;

FIG. 6 is a flowchart showing a control method according to the first embodiment;

FIG. 7 is a graph showing temperature characteristics according to the first embodiment;

FIG. 8 is a cross-sectional view of the MHP apparatus according to a second embodiment;

FIG. 9 is a cross-sectional view of the MHP apparatus according to a third embodiment;

FIG. 10 is a cross-sectional view of the MHP apparatus according to a fourth embodiment;

FIG. 11 is a cross-sectional view of the MHP apparatus according to a fifth embodiment;

FIG. 12 is a cross-sectional view of the MHP apparatus according to a sixth embodiment.

FIG. 13 is a cross-sectional view of the MHP apparatus according to a seventh embodiment;

FIG. 14 is a cross-sectional view of the MHP apparatus according to an eighth embodiment;

FIG. 15 is a cross-sectional view of the MHP apparatus according to a ninth embodiment;

FIG. 16 is a flowchart showing a control method according to the ninth embodiment;

FIG. 17 is a cross-sectional view of the MHP apparatus according to a tenth embodiment; and

FIG. 18 is a flowchart showing a control method according to the tenth embodiment.

DETAILED DESCRIPTION

Embodiments of the present disclosure are explained referring to drawings. In the embodiments, the same parts and components as those in each embodiment are indicated with the same reference numbers and the same descriptions will not be reiterated. In a case that only a part of component or part is described, other descriptions for the remaining part of component or part in the other description may be incorporated. Components and parts corresponding to the components and parts described in the preceding description may be indicated by the same reference number and may not be described redundantly. The embodiments may be partially combined or partially exchanged in some forms which are clearly specified in the following description. In addition, it should be understood that, unless trouble arises, the embodiments may be partially combined or partially exchanged each other in some forms which are not clearly specified.

First Embodiment

FIG. 1 is a block diagram showing a vehicle air-conditioner 10 for vehicle according to a first embodiment that practices the disclosure. The vehicle air-conditioner 10 has a magneto-caloric effect type heat pump apparatus 11. Hereinafter, the magneto-caloric effect type heat pump apparatus 11 may be referred as MHP apparatus 11. The MHP apparatus 11 provides the thermo-magnetic cycle apparatus.

In this specification, the word of the heat pump apparatus is used in a broad sense. That is, the word of the heat pump apparatus includes both of a heat pump apparatus using cold energy and a heat pump apparatus using hot energy. The heat pump apparatus using cold energy may correspond to a refrigerating cycle apparatus. The word of the heat pump apparatus may be used as a concept that includes the refrigerating cycle apparatus.

The MHP apparatus 11 has a magneto-caloric effect element. Hereinafter, the magneto-caloric effect element may be referred to as MCE element. The MCE element 12 produces both heat generation and heat absorption in response to strength change of an external magnetic field. The MCE element 12 generates heat in response to applying the external magnetic field, and absorbs heat in response to removing the external magnetic field. When the external magnetic field is applied to the MCE element 12, electron spins gather in the direction of the magnetic field. At this time, magnetic entropy decreases and the temperature is raised by emitting heat. When the external magnetic field is removed from the MCE element 12, the electron spins become to have disordered state. At this time, magnetic entropy increases and the temperature is lowered by absorbing heat. The MCE element 12 is made of magnetic substance which has a high magneto-caloric effect in an ordinary temperature region. For example, the MCE element 12 may be made of a Gadolinium(Gd)-base material or lanthanum-iron-silicon compound. Alternatively, a mixture of manganese, iron, phosphorus, and germanium may be used.

One MCE element 12 and components relevant to it provide a magneto-caloric element unit. The magneto-caloric element unit may be referred to as an MCD unit (Magneto-Caloric effect Device unit.) The MHP apparatus 11 uses magneto-caloric effect of the MCE element 12. The MHP apparatus 11 has a magnetic field modulating (MFM) device 13 and a heat transporting device 14 for operating the MCE element 12 as an AMR (Active Magnetic Refrigeration) cycle.

The MFM device 13 applies the external magnetic field to the MCE element 12, and varies the strength of the external magnetic field applied to the MCE element 12. The MFM device 13 periodically switches the magnetized state where the MCE element 12 is placed in a strong magnetic field and the demagnetized state where the MCE element 12 is placed in a weak magnetic field or a zero magnetic field. The MFM device 13 modulates the external magnetic field so that the external magnetic field periodically repeats a magnetized period PM when the MCE element 12 is placed in a strong magnetic field and a demagnetized period PN when the MCE element 12 is placed in the external magnetic field that is weaker than that in the magnetized period PM. The MFM device 13 has a magnetism source for generating the external magnetic field, for example, a permanent magnet, and an electromagnet.

The heat transporting device 14 has fluid devices for generating flow of a heat transport medium for transporting heat to be dissipated or absorbed by the MCE element 12. The heat transporting device 14 is a device which generates flow of the heat transport medium so that the heat transport medium flows along the MCE element 12 and performs heat exchange with the MCE element 12. The heat transporting device 14 generates flow of a heat transport medium so that a high temperature end and a low temperature end are generated on the MCE element 12. The heat transporting device 14 generates a bidirectional flow including a flow FM and a flow FN of the heat transport medium. The flow of the heat transport medium is the bidirectional flow FM, FN switched alternately in a synchronizing manner with change of the external magnetic field by the MFM device 13.

In this embodiment, the heat transport medium which carries out heat exchange to the MCE element 12 is called a primary medium. The primary medium can be provided by fluid, such as anti-freezing solution, water, and oil. The heat transporting device 14 generates a bidirectional flow of the heat transport medium. The heat transporting device 14 alternately changes flow directions of the heat transport medium in a forward and backward manner in a synchronizing manner with an increasing and decreasing changes of the external magnetic field by the MFM device 13. The heat transporting device 14 may have a pump for generating flow of the heat transport medium. The heat transporting device 14 has pumps 41 and 42 for generating flow of the primary medium. The pumps 41 and 42 supply the bidirectional flow of the primary medium for one MCE element 12. The pumps 41 and 42 are arranged on both ends of the MCE element 12. The pumps 41 and 42 are arranged to perform complementarily a suction process and a discharge process.

The MHP apparatus 11 has a motor 15 as a source of power. The motor 15 is the source of power for the MFM device 13. The motor 15 is the source of power for the heat transporting device 14.

The MHP apparatus 11 has a high-temperature system 16 which conveys high temperature created by the MHP apparatus 11. The high-temperature system 16 is also a thermal device which uses the high temperature created by the MHP apparatus 11. The MHP apparatus 11 has a low-temperature system 17 which conveys low temperature created by the MHP apparatus 11. The low-temperature system 17 is also a thermal device which uses the low temperature created by the MHP apparatus 11. The high-temperature system 16 and the low-temperature system 17 has heat exchangers 51 and 54 which provides heat exchange between the primary medium and a secondary medium, respectively. The primary medium is the heat transport medium. The structure of the heat exchangers 51 and 54 is shown and described in Japan patent application No. 2012-208318, content of which is incorporated by reference.

The high-temperature system 16 has a heat exchanger 51 which provides heat exchange between the primary medium and a secondary medium. The secondary medium is a heat transport medium used to convey thermal energy in the high-temperature system 16. The secondary medium can be provided by fluid, such as anti-freezing solution, water, and oil. The high-temperature system 16 has a passage 52 in which the secondary medium flows in a circulating manner. The high-temperature system 16 has a heat exchanger 53 which provides heat exchange between the secondary medium and the other medium. For example, the heat exchanger 53 provides heat exchange between the secondary medium and air. The high-temperature system 16 is also a device which removes heat, i.e., thermal energy, from the high-temperature end, and cools the high-temperature end.

The low-temperature system 17 has a heat exchanger 54 which provides heat exchange between the primary medium and a secondary medium. The secondary medium is a heat transport medium used to convey thermal energy in the low-temperature system 17. The secondary medium can be provided by fluid, such as anti-freezing solution, water, and oil. The low-temperature system 17 has a passage 55 in which the secondary medium flows in a circulating manner. The low-temperature system 17 has a heat exchanger 56 which provides heat exchange between the secondary medium and the other medium. For example, the heat exchanger 56 provides heat exchange between the secondary medium and air. The low-temperature system 17 is also a device which brings heat, i.e., thermal energy, to the low-temperature end, and heats the low-temperature end.

The vehicle air-conditioner 10 is mounted on a vehicle, and adjusts a temperature of passenger's cabin. Both heat exchangers 53 and 56 provide a part of the vehicle air-conditioner 10. The heat exchanger 53 is a high-temperature side heat exchanger 53 which becomes higher in temperature than that of the heat exchanger 56. The heat exchanger 53 is also called as an inside heat exchanger 53. The heat exchanger 56 is a low-temperature side heat exchanger 56 which becomes lower in temperature than that of the heat exchanger 53. The heat exchanger 56 is also called as an outside heat exchanger 56. The vehicle air-conditioner 10 also has air handling system components for using the high-temperature side heat exchanger 53 and/or the low-temperature side heat exchanger 56 for air-conditioning purposes, such as an air conditioning duct and a blower.

The vehicle air-conditioner 10 is used as a cooling device or a heating device. The vehicle air-conditioner 10 may have a cooling heat exchanger for cooling air to be supplied to the compartment, and a heating heat exchanger for heating air to be supplied to the compartment. The MHP apparatus 11 is used as a cold energy supply source or a hot energy supply source in the vehicle air-conditioner 10. That is, the high-temperature side heat exchanger 53 may be used as the heating heat exchanger. The low-temperature side heat exchanger 56 may be used as the cooling heat exchanger.

When the MHP apparatus 11 is used as a hot energy supply source, the air passing through the high-temperature side heat exchanger 53 is supplied to an interior of the compartment, and is used for heating. At this time, the air passing through the low-temperature side heat exchanger 56 is discharged to an outside of the vehicle. When the MHP apparatus 11 is used as a cold energy supply source, the air passing through the low-temperature side heat exchanger 56 is supplied to the interior of the compartment, and is used for cooling. At this time, the air passing through the high-temperature side heat exchanger 53 is discharged to an outside of the vehicle. The MHP apparatus 11 may be used as a dehumidifier system. In this case, the air first passes through the low-temperature side heat exchanger 56, and then passes through the high-temperature side heat exchanger 53, and then is supplied to the compartment. The MHP apparatus 11 may be used as a hot energy supply source also in both winter and summer.

The vehicle air-conditioner 1 has a controller (CNTR) 18. The controller 18 controls a plurality of controllable components of the vehicle air-conditioner 10. For example, the controller 18 controls the motor 15 to at least switch the MHP apparatus 11 in an activated mode and a deactivated mode.

The controller 18 is an electronic control unit. The controller 18 has a processing unit (CPU) and a memory (MMR) as a storage medium which memorizes a program. The controller 18 is provided by a microcomputer which has a storage medium which can be read by computer. The storage medium is a non-transitory storage medium which stores a program readable by the computer. The storage medium may be provided with semiconductor memory or a magnetic disc. The program, when the controller 18 executes the program, makes the controller 18 to function as the apparatus described in this specification, and makes the controller 18 to function to perform methods, such as control method, described in this specification. Means provided by the controller 18 may also be referred to as a functional block or a module, both of which performs a predetermined function.

MHP apparatus 11 has a temperature sensor 19. The temperature sensor 19 is used to detect or to estimate a temperature on an arbitrary part of the MCE element 12. This temperature may be referred to as an element temperature. The temperature on the arbitrary part of the MCE element 12 can be estimated based on the temperature detected by the temperature sensor 19. For example, a temperature on a high temperature end of the MCE element 12, a temperature on a low temperature end, or a temperature on a middle temperature portion between them may be estimated from the detected temperature of the temperature sensor 19. The temperature sensor 19 provides means for detecting or presuming the temperature of the arbitrary part of the MCE element 12.

In this embodiment, the temperature sensor 19 detects a surface temperature on the high temperature end of the MHP apparatus 11. In this case, the temperature detected by the temperature sensor 19 corresponds to the temperature on the high temperature end of the MCE element 12.

The MHP apparatus 11 has an auxiliary apparatus (AUXM) 61. The auxiliary apparatus 61 is provided separately and independently from the devices 16 and 17, which uses thermal energy generated on the high temperature end and/or on the low temperature end. The auxiliary apparatus 61 heats or cools a part of the MCE element 12 or the entire MCE element 12. Therefore, the auxiliary apparatus 61 adjusts the temperature of a part of the MCE element 12 or the entire MCE element 12. The auxiliary apparatus 61 is controlled by the controller 18. The controller 18 at least controls the auxiliary apparatus 61 into an activated mode and a deactivated mode. The controller 18 can control a heating quantity or a cooling quantity provided by the auxiliary apparatus 61.

The controller 18 has an initial control part (INTM) 18 a. The initial control part 18 a adjusts the element temperature of the MCE element 12 so that the element temperature approaches to the highly efficient temperature zone when the MCE element 12 is in an initial state in which the element temperature is out of the highly efficient temperature zone. The MCE element 12 demonstrates high performance when the element temperature of the MCE element 12 is in the highly efficient temperature zone. In a preferred embodiment, the initial control part 18 a adjusts the element temperature of the MCE element 12 so that at least a part of temperature on the MCE element 12 reaches the highly efficient temperature zone. Here, the highly efficient temperature zone is a temperature zone in which the MCE element 12 can generate a predetermined temperature difference between a high temperature end and a low temperature end by overcoming a thermal load by using an own magneto-caloric effect. The predetermined temperature difference is a temperature difference expected in a regular operation, and may also be referred to as a rated temperature difference. The initial control part 18 a adjusts a temperature of the MCE element 12 so that a temperature on the high temperature end of the MCE element 12 reaches a highly efficient temperature zone.

The initial control part 18 a adjusts the element temperature by controlling the auxiliary apparatus 61. The initial control part 18 a adjusts the element temperature by activating the auxiliary apparatus 61. The initial control part 18 a additionally controls the MFM device 13 and the heat transporting device 14 to operate the MHP apparatus 11 as a heat pump. The initial control part 18 a additionally controls the MFM device 13 and the heat transporting device 14 to make the MCE element 12 generates a high temperature end and a low temperature end on the ends thereof. The initial control part 18 a deactivates the auxiliary apparatus 61 when the MHP apparatus 11 is activated, i.e., when the MHP apparatus 11 reaches to operating condition from which the MHP apparatus 11 can excite itself by using own thermo-magnetic effect.

The controller 18 has a regular control part (REGM) 18 b. The regular control part 18 b controls the MFM device 13 and the heat transporting device 14 after adjustment of the element temperature by the initial control part 18 a is performed. The regular control part 18 b may begin own control after the initial control part 18 a finished the temperature control. The regular control part 18 b may begin own control after the initial control part 18 a completed the temperature control. The regular control part 18 b may begin own control after starting the temperature control of the initial control part 18 a but initial control part 18 a is still performing the temperature control. The regular control part 18 b controls the MFM device 13 and the heat transporting device 14 to operate the MHP apparatus 11 as a heat pump. The regular control part 18 b controls the MFM device 13 and the heat transporting device 14 to make the MCE element 12 generates a high temperature end and a low temperature end on the ends thereof.

FIG. 2 is a cross-sectional view of the MHP apparatus 11 according to the first embodiment. FIG. 3 is a cross-sectional view of the MHP apparatus 11 according to the first embodiment. FIG. 2 shows a cross-section on II-II line shown in FIG. 3. FIG. 3 shows a cross-section on III-III line shown in FIG. 2.

A motor 15, which is disposed as a power source of the MHP apparatus 11, is driven by a battery mounted on the vehicle. The motor 15 rotates a rotor 13 which provides the MFM device 13. Thereby, the motor 15 and the MFM device 13 create a periodic alternating change between a condition in which an external magnetic field is applied to the MCE element 12 and a condition in which the external magnetic field is removed from the MCE element 12. The condition in which the external magnetic field is removed may corresponds to a condition in which the external magnetic field is not applied to the MCE element 12 or just reduced from the applied condition. The motor 15 drives and activates pumps 41 and 42 of the heat transporting device 14. Thereby, the motor 15 and the pumps 41 and 42 supply a bidirectional flow of the primary medium for one MCE element 12.

The pumps 41 and 42 produce bidirectional flow of the primary medium in the MCD unit in order to be worked the MCE element 12 as the AMR cycle. The pumps 41 and 42 are displacement-type bidirectional flow pumps. The pumps 41 and 42 are cam-plate type piston pumps. The pumps 41 and 42 are axial piston pumps having a plurality of cylinders. One cylinder of the pump 41 and one cylinder of the pump 42 are arranged to one MCE element 12. Two cylinders arranged on one MCE element 12 to function complementarily. Thereby, the pumps 41 and 42 supply the bidirectional flow of the primary medium flowing along the longitudinal direction of one MCE element 12. In this embodiment, the MHP apparatus 11 has a plurality of MCE elements 12 which are connected in thermally parallel. In the MHP apparatus 11, eight MCE elements 12 are connected in thermally parallel. Therefore, each one of the pumps 41 and 42 has 8 cylinders.

The MHP apparatus 11 has a housing 21 which may be called as a circular cylindrical or a circular columnar shape. The housing 21 supports the rotary shaft 22 rotatably on a central axis of the housing 21. The rotary shaft 22 is connected with the output shaft of the motor 15. The housing 21 defines an accommodation chamber 23 for accommodating the MFM device 13 around the rotary shaft 22. The accommodation chamber 23 is formed in a shape like a circular columnar shape. A rotor core 24 is fixed to the rotary shaft 22. The rotor core 24 and the housing 21 provide yoke members for guiding and passing the magnetic flux. The rotor core 24 is configured to form a range which is easy to pass through the magnetic flux along the circumferential direction thereof and a range which is hard to pass through the magnetic flux. A permanent magnet 25 is fixed to the rotor core 24. A plurality of magnets 25 are fixed on the rotor core 24. The permanent magnet 25 is formed in a semi-cylindrical shape which has a fan-shaped cross section. The permanent magnet 25 is fixed on a radial outside surface of the rotary shaft 22.

The rotor core 24 and the permanent magnet 25 form regions around them. One region is that the external magnetic field provided by the permanent magnet 25 is strong. The other one region is that the external magnetic field provided by the permanent magnet 25 is weak. In the region in which the external magnetic field is weak, a state in which the external magnetic field is almost completely removed is provided. The rotor core 24 and the permanent magnet 25 rotate in a synchronizing manner with a revolution of the rotary shaft 22. Therefore, the region of strong external magnetic field and the region of weak external magnetic field rotate synchronizing with the revolution of the rotary shaft 22. As a result, at one point on a circumference of the rotor core 24 and the permanent magnet 25, a period when the external magnetic field is strongly applied and a period when the external magnetic field becomes weak and was almost removed are alternately appears. Therefore, the rotor core 24 and the permanent magnet 25 provide the MFM device 13 which alternates the applied state and the removed state of the external magnetic field. The rotor core 24 and the permanent magnet 25 provide a device which alternately switches the state applying the external magnetic field to the MCE element 12 and the state removing the external magnetic field from the MCE element 12. The word of the magnetic field is interchangeable with magnetic flux density or magnetic field strength.

The housing 21 defines at least one work chamber 26. The work chamber 26 is located next to the accommodation chamber 23. The housing 21 defines a plurality of work chambers 26 arranged at equal intervals on a radial outside of the accommodation chamber 23. In this embodiment, one housing 21 defines eight work chambers 26. Each of the work chambers 26 forms a columnar-shaped chamber which has a longitudinal direction along the axial direction of the housing 21. One work chamber 26 is formed so that it corresponds to one cylinder of the pump 41 and one cylinder of the pump 42. Two cylinders are arranged on both sides of one work chamber 26.

The work chamber 26 provides a channel where the primary medium flows. The primary medium flows along a longitudinal direction of the work chamber 26. The primary medium flows along a longitudinal direction of the work chamber 26 in a bidirectional manner in which flow directions are alternately switched in one direction and the other opposite direction.

The work chamber 26 also provides an accommodation chamber in which the MCE element 12 is accommodated. The housing 21 provides a container in which the work chamber 26 is formed. The MCE element 12 which provides a magnetic working material having magneto-caloric effect is disposed in the work chamber 26.

One MCE element 12 is formed in a columnar shape, i.e., a rod shape, having a longitudinal direction along an axial direction of the MHP apparatus 11. The MCE element 12 is formed in a shape which can provides sufficient heat exchange with the primary medium flowing through within the work chamber 26. Each MCE element 12 may also be called an element bed.

The MCE element 12 is placed under an effect of the external magnetic field switched between an applied state and a removed state by the MFM device 13. That is, as the rotary shaft 22 rotates, it is performed to switch the applied state in which the external magnetic field for magnetizing the MCE element 12 is applied and the removed state in which the external magnetic field is removed from the MCE element 12.

The auxiliary apparatus 61 has a heater (HTDV) 62. The heater 62 is an electric heater. Thermal energy generated by the heater 62 is supplied to the heat exchanger 63. The heat exchanger 63 is attached to the heat exchanger 51. The heat exchanger 63 can be provided by a connecting member which connects the heater 62 and the heat exchanger 51 in a thermally conductive manner. The heat exchanger 63 conveys the thermal energy supplied from the heater 62 to a member of the heat exchanger 51. The heat exchanger 51 is also a member which defines a flow channel of the primary medium. Accordingly, the thermal energy supplied from the heater 62 is conveyed to the heat transport medium which is the primary medium. Since the primary medium flows along the MCE element 12, the thermal energy supplied from the heater 62 is transmitted to the MCE element 12 via the primary medium. As a result, the MCE element 12 is heated by the heater 62. In a structure shown in the drawings, since the heat exchanger 63 is attached onto the heat exchanger 51 which is associated with the high temperature end of the MCE element 12, the heater 62 heats the high temperature end of the MCE element 12.

The heat exchanger 63 provides a heat exchanger which performs heat exchange between the auxiliary apparatus 61 and the MCE element 12. The heat exchanger 63 performs heat exchange with the heat transport medium which is the primary medium. The heat exchanger 51 is a member which defines a passage through which the heat transport medium flows. The heat exchanger 63 is disposed on this member. The heat exchanger 63 is also a heat exchanger for performing heat exchange with the secondary medium.

As shown in FIG. 3, the permanent magnet 25 is fixed on a radial outside surface of the rotary shaft 22. The permanent magnet 25 is disposed over an angular range PM. The angular range PM may be referred to as an applying period in which the external magnetic field is applied to one MCE element 12, i.e., a magnetized period PM. The MFM device 13 has the permanent magnet 25 that has a size corresponding to the magnetized period PM. The permanent magnet 25 is not disposed over an angular range PN. The angular range PN may also be referred to as a removal period in which the external magnetic field is removed from one MCE element 12, i.e., a demagnetized period PN. Demagnetized period does not mean condition where magnetic field is zero. Demagnetized period includes condition where magnetic field, which is weaker than magnetic field in the magnetized period PM, is still applied.

Since the MCE element 12 generates heat in the magnetized period PM, the pumps 41 and 42 are operated to make the primary medium flows toward the high-temperature system 16. As a result, the primary medium flows toward the high-temperature system 16 for a first period of time. On the other hand, since the MCE element 12 absorbs heat in the demagnetized period PN, the pumps 41 and 42 are operated to make the primary medium flows toward the low-temperature system 17. As a result, the primary medium flows toward the low-temperature system 17 for a second period of time. The magnetized period PM and the first period overlap in major range of them. The magnetized period PM and the first period may shift slightly at a starting range and an ending range of them. The demagnetized period PN and the second period overlap in major range of them. The demagnetized period PN and the second period may shift slightly at a starting range and an ending range of them. A flow amount of the primary medium flowing toward the high-temperature system 16 in the first period and a flow amount of the primary medium flowing toward the low-temperature system 17 in the second period are equal. The heat transporting device 14 provides the same flow amounts in each of flow directions of the bidirectional flow FM, FN.

Returning to FIG. 2, one MCE element 12 has a plurality of element units 12 a-12 f. The element units 12 a-12 f are arranged by stacking or laminating along a flow direction of the primary medium, i.e., a longitudinal direction of the MCE element 12. The plurality of element units 12 a-12 f are made of different material which are differ in Curie temperature. The element units 12 a-12 f demonstrate high magneto-caloric effects (Delta-S (J/kgK)) in different temperature zones, respectively. The element unit 12 f near the high temperature end has the material composition which demonstrates a high magneto-caloric effect at a temperature range near a temperature which appears on the high temperature end at a regular operating condition. The element unit 12 c near the middle temperature portion has the material composition which demonstrates a high magneto-caloric effect at a temperature range near a temperature which appears on the middle temperature portion at the regular operating condition. The element unit 12 a near the low temperature end has the material composition which demonstrates a high magneto-caloric effect at a temperature range near a temperature which appears on the low temperature end at the regular operating condition. The element units 12 a-12 f are arranged to place one element unit, e.g., the element unit 12 f, on a position closer to the high temperature end than the other element unit, e.g., the element unit 12 e. The one element unit, e.g., the element unit 12 f, demonstrates a significant magneto-caloric effect at a temperature which is higher than a temperature where the other element unit, e.g., the element unit 12 f, demonstrates a significant magneto-caloric effect.

FIG. 4 shows magneto-caloric effect of the plurality of element units 12 a-12 f. A diagram 4A in the drawing shows an arrangement of the element units 12 a-12 f. A diagram 4B in the drawing shows temperature on the horizontal axis and magneto-caloric effects on the vertical axis. In the drawing, one waveform shows a characteristic of one element unit. For example, the waveform S12 f shows a characteristic of the element unit 12 f.

A temperature zone with which a high magneto-caloric effect is demonstrated is called as a highly efficient temperature zone. An upper limit temperature and a lower limit temperature of the highly efficient temperature zone depend on material composition of the MCE element 12, etc. The element units 12 a-12 f are arranged in series so that the highly efficient temperature zones are located in a side-by-side manner between the high temperature end and the low temperature end. In other words, the highly efficient temperature zones of the element units 12 a-12 f show distribution having a shape of a stairway which is lowered step-by-step manner from the high temperature end between the high temperature end and the low temperature end. This stairway shaped distribution of the highly efficient temperature zones is mostly equivalent to a temperature distribution between the high temperature end and the low temperature end in a regular state.

A plurality of element units 12 a-12 f shares a regular temperature difference which is created between the high temperature end and the low temperature end in the regular operation. Thereby, high effectiveness can be acquired in each of the element units. In other words, the element units 12 a-12 f is adjusted so that each of the element units can demonstrates the magneto-caloric effect exceeding the predetermined threshold value Sth when the regular temperature difference is acquired.

As shown in the drawing, one element unit demonstrates the magneto-caloric effect exceeding the first predetermined threshold value in the predetermined first temperature range. Other element unit which adjoins the one element unit demonstrates the magneto-caloric effect exceeding the second predetermined threshold value in the second temperature range which is shifted from the first temperature range to a high-temperature side or a low-temperature side. Waveforms showing the characteristics of the element units are arranged and set up to overlap each other. For example, at a temperature T6 where the element unit 12 f demonstrates the maximum magneto-caloric effect, the adjoining element unit 12 e demonstrates a magneto-caloric effect which is higher than the minimum value but lower than a peak value.

In this embodiment, each of the element units 12 a-12 f demonstrates the magneto-caloric effect exceeding the threshold value Sth in corresponding temperature range which is assigned to the unit to be taken charge of. All element units can demonstrate the magneto-caloric effect over the threshold value Sth when each unit works in the corresponding assigned temperature range. A temperature difference between the low temperature end and the high temperature end obtained in the regular operation, i.e., a temperature range equivalent to the rated temperature difference, is covered by the plurality of element units 12 a-12 f, without having an excessive valley or excessive sag on total magneto-caloric effect.

In the drawing, circular marks show operating points where the highest magneto-caloric effect can be demonstrated. For example, the element unit 12 b demonstrates the highest magneto-caloric effect at a temperature T2. The element unit 12 f demonstrates the highest magneto-caloric effect at a temperature T6.

At the time of starting of the MHP apparatus 11, the whole MCE element 12 may become the same temperature. For example, when the MHP apparatus 11 is placed on low temperature environment like winter, the element temperature of the MCE element 12 becomes the same low temperature as an outside temperature. In the drawing, a square mark shows an operating point in one example at a starting stage of the MHP apparatus. In this example, the whole MCE element 12 is temperature T1. Thereby, the element unit 12 a may demonstrate the highest magneto-caloric effect. However, the adjoining element unit 12 b can demonstrate only a low specified value Si. Furthermore, the element units 12 c-12 f located on a high-temperature side can demonstrate only the magneto-caloric effect which is less than the specified value Si. In such a case, even if the MHP apparatus 11 is activated, a long time shall be taken until the high temperature end of the MCE element 12 reaches to a regular temperature in the regular operation. In other words, a long time is required in order to generate sufficient temperature difference between the ends of the MCE element 12. There may be a case in which the high temperature end of the MCE element 12 cannot reach to the regular temperature in the regular operation. In other words, sufficient temperature difference between the ends of the MCE element 12 cannot be generated.

In the drawing, triangle marks show operating points in case the MCE element 12 is heated by the auxiliary apparatus 61. When the auxiliary apparatus 61 heats the MCE element 12, the element temperature on the high temperature end of the MCE element 12 is increased. Simultaneously, temperature on the plurality of element units 12 a-12 f also rise according to an amount of heat conduction from the auxiliary apparatus 61 and an amount of heat dissipation, etc.

For example, a temperature of the high temperature end of the MCE element 12, i.e., the temperature of the element unit 12 f reaches a temperature T61. The element unit 12 f demonstrates a magneto-caloric effect with a predetermined value Ssp which is higher than the predetermined value Si at a beginning period of staring. The predetermined value Ssp may be referred to as an assisted magneto-caloric effect which is acquired as a result of the auxiliary temperature control. A temperature of the element unit 12 b also reaches a temperature T21. The element unit 12 b demonstrates a magneto-caloric effect with a predetermined value Ssp which is higher than the predetermined value Si.

Thus, in a case that the MCE element 12 is heated by the auxiliary apparatus 61, the element unit 12 a, 12 b, and 12 f demonstrate a magneto-caloric effect higher than the predetermined value Si. These element units 12 a, 12 b, and 12 f generate temperature differences on respective ends by own magneto-caloric effect, and enlarge the temperature difference further. As a result, the high temperature end of the MCE element 12 reaches the regular temperature in the regular operation in short time from the beginning of operation of the MHP apparatus 11. In other words, a sufficient temperature difference can be generated between the ends in a short time.

Once the MCE element 12 becomes possible to generate a temperature difference and to maintain the temperature difference by own magneto-caloric effect, the auxiliary temperature control by the auxiliary apparatus 61 can be completed. Thus, the auxiliary apparatus 61 assists starting of the MHP apparatus 11, and make it possible to shorten a time which is necessary to start up the MHP apparatus 11. Furthermore, since the auxiliary apparatus 61 stops auxiliary temperature control in the regular operational status, it is possible to reduce energy consumption.

FIG. 5 shows temperature distribution on the plurality of element units 12 a-12 f. 5A in the drawing shows an arrangement of the plurality of element units 12 a-12 f. In 5B in the drawing, the horizontal axis shows location on the plurality of element units 12 a-12 f, and the vertical axis shows temperature.

The MCE element 12 demonstrates the highest magneto-caloric effect at the high performance temperature Tef shown by circular marks. In a case of an example of starting in a low temperature environment, the initial temperature Tin of the MCE element 12 may be the initial temperature TinL shown by square marks. In the drawing, the initial temperature TinL is a temperature T1 that is equal to the high performance temperature Tef of the element unit 12 a on the low temperature end. The auxiliary apparatus 61 heats the high temperature end of the MHP apparatus 11 by the heater 62. Thereby, the element temperature of the MCE element 12 changes to the auxiliary heating temperature Tsp shown by triangle marks. In this embodiment, since the auxiliary apparatus 61 heats only the high temperature end of the MCE element 12, a temperature distribution illustrated may appear on the MCE element 12.

The initial control part 18 a heats the high temperature end so that the element temperature of the element unit 12 f reaches near the high performance temperature Tef from the initial temperature TinL. Heating capacity of the heater 62 is set up so that the heater 62 can raise and increase the element temperature of the element unit 12 f on the high temperature end to reach to a temperature near the high performance temperature Tef=T6 when an environmental temperature is equal to the high performance temperature Tef of the element unit 12 a on the low temperature end, i.e., a temperature T1. The initial control part 18 a makes the element temperature of the element unit 12 f on the high temperature end to reach to the temperature T61 which is higher than the high performance temperature Tef=T5of the element unit 12 e located next to the element unit 12 f. In other words, the initial control part 18 a heats the high temperature end so that the element temperature of the element unit 12 f on the high temperature end reaches near the temperature as which the element unit 12 f works a magneto-caloric element, i.e., Curie temperature. Thereby, the element unit 12 f on the high temperature end demonstrates a high magneto-caloric effect.

In addition, other element units 12 b-12 e are heated. Therefore, other element units 12 b-12 e also demonstrate high magneto-caloric effects. For example, the element temperature of the element unit 12 b is heated from the initial temperature T1 to a temperature T21. Thereby, the element unit 12 b may demonstrate a high magneto-caloric effect.

An amount of temperature adjustment by the auxiliary apparatus 61 is set up to reduce or prevent demagnetization of the permanent magnet 25. In other words, the initial control part 18 a adjusts the element temperature of the MCE element 12 so that demagnetization of the permanent magnet 25 is reduced. The initial control part 18 a adjusts the temperature of the MCE element 12 so that irreversible demagnetization of the permanent magnet 25 is reduced. The initial control part 18 a controls the auxiliary apparatus 61 so that the element temperature of the element unit 12 f reaches a temperature T61 which is slightly lower than the high performance temperature Tef=T6. According to this structure, demagnetization resulting from a temperature of the permanent magnet 25 and irreversible demagnetization resulting from a high temperature or a low temperature caused by temperature adjustment performed by the initial control part 18 a may be reduced.

FIG. 6 shows a flowchart which shows a control processing 170 for the MHP apparatus 11 performed by the controller 18. At step 171, it is determined that whether it is in a starting period after the MHP apparatus 11 is just started. For example, it is determined that whether it is after a turned off period over a long time period in which the MCE element 12 may reach to an environmental temperature, and it is within a predetermined period after the MHP apparatus 11 is started. If it is not in the starting period, the processing progresses to step 176. If it is in the starting period, the processing progresses to step 172.

At step 172, starting control for making the element temperature of the MCE element 12 shift from the initial temperature Tin to the high performance temperature Tef is performed. Step 172 may contain step 173 and step 174. The auxiliary apparatus 61 is activated at step 173. Thereby, the high temperature end of the MCE element 12 is heated by the heater 62 and the heat exchanger 63. At step 174, in order to operate the MHP apparatus 11, the MFM device 13 and the heat transporting device 14 are activated. Thereby, the external magnetic field applied to a part of the MCE element 12 is modulated in an alternately increased and decreased manner. Simultaneously, the primary medium alternately flows in a forward direction and a backward direction in a synchronizing manner with the change of the external magnetic field.

In step 174, the element units 12 a-12 f works as a heat pump in a period in which the element temperature of the element units 12 a-12 f changes from the initial temperature Tin towards the auxiliary heating temperature Tsp, and a period in which the element temperature of the element units 12 a-12 f changes from the auxiliary heating temperature Tsp towards the high performance temperature Tef. In the starting control, the element units 12 a-12 f change, i.e., by heating or cooling, the element temperature of the element units 12 a-12 f to approach toward the high performance temperature Tef from the initial temperature Tin by using the magneto-caloric effect of themselves. In addition, in the starting control, the auxiliary apparatus 61 changes, i.e., heats, the element temperature of the element units 12 a-12 f to approach towards the high performance temperature Tef from the initial temperature Tin. In the starting control, at least a part of the element units cannot function at the high performance temperature Tef. Accordingly, it may take a long time to reach to the high performance temperature Tef, or may be unable to reach the high performance temperature Tef by only using the magneto-caloric effect of the MCE element 12. However, in this embodiment, since the auxiliary apparatus 61 is activated in the starting control, starting of the MHP apparatus 11 can be promoted.

At step 175, it is determined whether the termination conditions of the starting control by step 172 were fulfilled. Step 172 is repeated when the starting control is not terminated. The starting control has been terminated, then, the processing progresses to step 176. At step 175, the determination may be performed by determining whether a temperature of a portion under temperature control by the auxiliary apparatus 61 reaches to a target temperature or not. The target temperature may be the Curie temperature of the element unit located on the portion where the auxiliary apparatus 61 supplies heat, for example. In this case, at least the element unit located on the portion can be activated and operated with high performance.

In this example, the high temperature end of the MCE element 12 is heated, and the temperature sensor 19 detects the temperature on the high temperature end. In this case, the determination at step 175 can be provided by a determination of whether the temperature of the element unit 12 f reaches the high performance temperature T6or not. In other examples, the low temperature end of the MCE element 12 may be cooled, and the temperature sensor 19 detects the temperature on the low temperature end. In this case, the determination at step 175 can be provided by a determination of whether the temperature of the element unit 12 a reaches the high performance temperature T1or not. Furthermore, in other examples, the middle portion of the MCE element 12 is heated or cooled, and the temperature sensor 19 detects or presumes the temperature on the middle portion. In this case, the determination at step 175 can be provided by a determination of whether the temperature of the element unit 12 c or 12 d reaches the high performance temperature T3or T4or not.

The target temperature in step 175 is set up to reduce demagnetization of the permanent magnet 25 or to avoid generating demagnetization of the permanent magnet 25. In a case that the auxiliary apparatus 61 heats the MCE element 12, in order to avoid generating irreversible demagnetization of the permanent magnet 25, the target temperature is set up to be less than a high-temperature range in which the permanent magnet 25 may get irreversible demagnetization. In a case that the auxiliary apparatus 61 cools the MCE element 12, in order to avoid generating irreversible demagnetization of the permanent magnet 25, the target temperature is set up to be higher than a high-temperature range in which the permanent magnet 25 may get irreversible demagnetization. Thus, the target temperature is set to avoid temperature range in which the permanent magnet 25 generates irreversible demagnetization.

At step 176, a regular control for performing a regular operation or a regular steady operation of the MHP apparatus 11 is performed. Step 176 may contain step 177. At step 177, in order to work the MHP apparatus 11 as the AMR cycle, the MFM device 13 and the heat transporting device 14 are activated. Thereby, the external magnetic field applied to a part of the MCE element 12 is modulated in an alternately increased and decreased manner. Simultaneously, the primary medium alternately flows in a forward direction and a backward direction in a synchronizing manner with the change of the external magnetic field. At step 177, each of the element units 12 a-12 f functions at each of the high performance temperatures T1-T6. As a result, the MHP apparatus 11 demonstrates the high heat pump performance expected.

The auxiliary apparatus 61 is deactivated under the regular control. That is, heating by the heater 62 is stopped. Therefore, it is possible to avoid that the heater 62 is operated over a long time period.

In FIG. 7, the horizontal axis shows temperature TEMP and the vertical axis shows the average work performance Delta-S of the material of the MCE element 12. In the drawing, a start-limit line Lmt shows a border line where the MHP apparatus 11 can works as a heat pump or not. In the illustrated embodiment, the start-limit line Lmt shows a limit line, i.e., a lower limit, therefore, when an operating point, i.e., the temperature, is higher than the star-limit line Lmt the MHP apparatus 11 can enlarge the temperature difference between the high temperature end and the low temperature end. When the operating point of the MHP apparatus 11 is less than the start-limit line Lmt, the MHP apparatus 11 cannot enlarge the temperature difference between the high temperature end and the low temperature end. In the drawing, the temperature shown on the horizontal axis corresponds to a temperature difference between the low temperature end and the high temperature end. Here, a case where the low temperature end is constant temperature is illustrated, therefore, the horizontal axis shows the temperature of the high temperature end.

In case that the apparatus has no auxiliary apparatus 61, it is necessary to set an operating line CMP not less than the start-limit line Lmt as shown in a broken line. At the time of starting, the operating point gradually moves from the operating point shown by the square mark at the initial temperature Tin toward the operating point, the regular operating point, shown by the circular mark at the regular temperature TH. The operating line CMP is set up not to intersect with the start-limit line Lmt over an expected temperature range from Tin to TH. Only a low magneto-caloric effect Sc may be acquired by this operating line CMP.

In this embodiment, as shown by solid line, an operating line EMB can be set without limitation caused by the start-limit line Lmt. At the time of starting, the operating point gradually moves from the operating point shown by the square mark at the initial temperature Tin toward the operating point, the regular operating point, shown by the circular mark at the regular temperature TH. The auxiliary apparatus 61 can heat the MCE element 12 to the auxiliary heating temperature Tsp shown by the triangular mark. The auxiliary heating temperature Tsp is the temperature higher than the start-limit line Lmt. According to this structure, since the auxiliary apparatus 61 provide the temperature exceeding the start-limit line Lmt at the time of starting, the MHP apparatus 11 can be started as a heat pump without being restricted by the start-limit line Lmt. In this structure, although the operating line EMB intersects the start-limit line Lmt, it provides a higher magneto-caloric effect Se.

According to this structure, regular operation of the MCE element 12 using the MFM device 13 and the heat transporting device 14 is provided by the regular control part 18 b. In advance of the regular operation performed by the regular control part 18 b, the initial control part 18 a adjusts the element temperature of the MCE element 12. In the initial state in which the element temperature is out of the highly efficient temperature zone, the initial control part 18 a adjusts the element temperature toward the highly efficient temperature zone. Accordingly, the temperature control by the initial control part 18 a is provided only in the initial state. Therefore, it is possible to eliminate adverse effect by the initial control part 18 a when the apparatus is in the regular operation.

Second Embodiment

This embodiment is one of modifications based on a basic form provided by the preceding embodiment. In the preceding embodiment, the auxiliary apparatus 61 uses a heater 62. Alternatively, or additionally, in this embodiment, a cooler that cools a part of or all of the MCE element 12 is used for the auxiliary apparatus 61.

In FIG. 8, the auxiliary apparatus 61 has the cooler (CLDV) 264 which cools the MCE element 12. The cooler 264 may be provided by variety of devices which can supply cold energy, i.e., low temperature. For example, the cooler 264 may be provided by Peltier device which produces low temperature electrically. The cooler 264 may be provided by a refrigerating cycles, such as a steam compression type cycle. The cooler 264 may be provided by the apparatus using the coolant which takes a thermal energy with evaporative latent heat, for example, cooling spray equipment.

Low temperature provided by the cooler 264 is supplied to a heat exchanger 263. The heat exchanger 263 is attached on the heat exchanger 54. The heat exchanger 263 can be provided by a connecting member which connects the cooler 264 and the heat exchanger 54. The heat exchanger 263 conducts cold energy supplied from the cooler 264 to the member of the heat exchanger 54. The heat exchanger 54 is also a member which defines the channel for the primary medium. Accordingly, the thermal energy supplied from the cooler 264 is conducted to the heat transport medium which is the primary medium. Since the primary medium flows along the MCE element 12, the thermal energy supplied from the cooler 264 is conveyed to the MCE element 12 via the primary medium. As a result, the MCE element 12 is cooled by the cooler 264. With the structure illustrated, since the heat exchanger 263 is attached on the heat exchanger 54 associated with the low temperature end of the MCE element 12, the cooler 264 cools the low temperature end of the MCE element 12.

The heat exchanger 263 provides the heat exchange device which performs heat exchange between the auxiliary apparatus 61 and the MCE element 12. The heat exchanger 263 performs heat exchange with the heat transport medium which is the primary medium. The heat exchanger 54 is a member which defines the passage through which the heat transport medium flows. The heat exchanger 263 is disposed on this member. The heat exchanger 263 is also a heat exchanger which carries out heat exchange with the secondary medium.

In a case that the MHP apparatus 11 is located on a high temperature environment, the element temperature of the MCE element 12 may exceed the high performance temperature Tef of some element units. In a case of example to start the apparatus in such a high temperature environment, the initial temperature Tin of the MCE element 12 may be the initial temperature TinH shown in FIG. 5 with a broken line. In this case, the auxiliary apparatus 61 cools the MCE element 12. For example, the auxiliary apparatus 61 cools the low temperature end of the MCE element 12.

In this case, the controller 18 is also adopted. The initial control part 18 a activates the auxiliary apparatus 61, i.e., the cooler 264. The initial control part 18 a adjusts the element temperature so that the temperature on the low temperature end of the MCE element 12 reaches to the highly efficient temperature zone.

Third Embodiment

This embodiment is one of modifications based on a basic form provided by the preceding embodiment. In the preceding embodiment, the temperature of the high temperature end or the low temperature end of the MCE element 12 is adjusted. Alternatively, in this embodiment, a temperature of the middle portion between the high temperature end and the low temperature end of the MCE element 12 is adjusted.

As shown in FIG. 6, a heat exchanger 363 is disposed on the middle portion of the housing 21. The heat exchanger 363 indirectly controls temperature of the middle portion of the MCE element 12 by conducting the cold energy supplied from a cooler 264 to the housing 21. The initial control part 18 a adjusts the element temperature so that the temperature on the middle portion of the MCE element 12 reaches to the highly efficient temperature zone.

Fourth Embodiment

This embodiment is one of modifications based on a basic form provided by the preceding embodiment. In the preceding embodiment, the element temperature is indirectly adjusted from a surface of a member which constitutes the MHP apparatus 11. Alternatively, in this embodiment, a heat exchange device which performs heat exchange directly with the secondary medium is used.

As shown in FIG. 10, a heat exchanger 463 is disposed on the passage 55. The heat exchanger 463 provides heat exchange between the secondary medium flowing through the passage 55 and the cooler 264.

Fifth Embodiment

This embodiment is one of modifications based on a basic form provided by the preceding embodiment. The preceding embodiment employs the heater 62 or the cooler 264. Alternatively, or additionally, in this embodiment, a thermal storage which can store thermal energy such as hot energy or cold energy, and can discharge the stored thermal energy is used.

As shown in FIG. 11, the auxiliary apparatus 61 has a thermal storage 565. The thermal storage 565 stores low temperature, i.e., cold energy acquired during the period the MHP apparatus 11 is operating. The thermal storage 565 cools the low temperature end of the MCE element 12 by discharging the stored cold energy. Thus, the auxiliary apparatus 61 has the thermal storage 565 which stores the temperature obtained on the high temperature end or the low temperature end. The thermal storage 565 can also be applied to embodiments which heats or cools the high temperature end or the middle temperature portion of the NICE element 12. The thermal storage 565 can be used together with the heater 62 and/or the cooler 264.

Sixth Embodiment

This embodiment is one of modifications based on a basic form provided by the preceding embodiment. In this embodiment, a heat exchange device for adjusting the element temperature has an original heat transport medium.

As shown in FIG. 12, the heat exchange device 663 is disposed between the cooler 264 and the heat exchanger 54. The heat exchange device 663 has a pump, a primary heat exchanger, a secondary heat exchanger, and a heat-transport-medium passage which connects the above components in a ring circuit. According to this structure, the cooler 264 adjusts the element temperature indirectly via the heat exchange device 663.

Seventh Embodiment

This embodiment is one of modifications based on a basic form provided by the preceding embodiment. In this embodiment, the high temperature end of the MCE element 12 is heated, and also, the low temperature end is cooled.

As shown in FIG. 13, the auxiliary apparatus 61 has both the heater 62 and the cooler 264. According to this structure, the temperature of both the high temperature end and the low temperature end can be adjusted near the desirable temperature, for example, the high performance temperature Tef.

Eighth Embodiment

This embodiment is one of modifications based on a basic form provided by the preceding embodiment. In the preceding embodiment, the MHP apparatus 11 conveys the thermal energy to the outside by using the secondary medium. Alternatively, in this embodiment, the thermal energy is conveyed to the outside by using the primary medium.

FIG. 14 shows an MHP apparatus 11 according to this embodiment. The MHP apparatus 11 has a valve system 857 and 858. The valve system 857 and 858 make it possible to take a part of the heat transport medium, which is the primary medium, out to the outside. The valve system 857 and 858 provide a suction valve and a discharge valve corresponding to each of a plurality of MCE elements 12. The valve system 857 and 858 provide a channel for taking out the primary medium to the outside. For example, the valve system 858 provides the suction valve 859 a and the discharge valve 859 b between one MCE element 12 and corresponding one of the cylinder of the pump 42. As shown in the drawing, a heat exchanger 863 is disposed on a passage between the pump 42 and the suction valve 859 a.

The high-temperature system 16 is provided by the valve system 857 and a heat exchanger 853 which carries out heat exchange with the heat transport medium taken out via the valve system 857. The low-temperature system 17 is provided by the valve system 858 and a heat exchanger 856 which carries out heat exchange with the heat transport medium taken out via the valve system 858.

According to this structure, by using no secondary medium, it is possible to take thermal energy from the MHP apparatus 11 by using the primary medium, and also to supply thermal energy to the MHP apparatus 11 by using the primary medium. The structure of this embodiment is shown and described in Japan patent application No. 2012-128820, content of which is incorporated by reference.

Ninth Embodiment

This embodiment is one of modifications based on a basic form provided by the preceding embodiment. In the preceding embodiment, the element temperature is adjusted by using the auxiliary apparatus 61. Alternatively or additionally, in this embodiment, the element temperature of the MCE element 12 is actively adjusted by a thermal function different from the magneto-caloric effect by using a heat generating capacity of the MHP apparatus 11.

As shown in FIG. 15, an initial control part 918 a is adopted in this embodiment. The initial control part 918 a controls a device which belongs to the MHP apparatus 11 so that the MHP apparatus 11 generates heat. The initial control part 918 a controls the MFM device 13 and the heat transporting device 14 to generate heat. The regular control part 18 b also controls the MFM device 13 and the heat transporting device 14. The MFM device 13 and the heat transporting device 14 provide a regular operation condition when both are controlled by the regular control part 18 b. The initial control part 918 a controls the MFM device 13 and the heat transporting device 14 to provide an initial operation condition which is different from the regular operation condition. A greater amount of heat is generated in the initial operation condition than that in the regular operation condition in the MHP apparatus 11.

As shown in FIG. 16, steps 973 and 974 are employed in this embodiment. At step 973, the initial control is performed. The initial control is provided by a processing for performing setting of the MHP apparatus 11 for the initial operation condition. For example, the initial control sets the MHP apparatus 11 to operate the motor 15 at a higher rotational speed than that in the regular operation. At step 974, devices in the MHP apparatus 11 are controlled based on the setting set at step 973.

For example, in the initial operation condition, the rotating speed of the motor 15 and the rotating speed of the pumps 41 and 42 are set up more highly than that in the regular operation condition. As a result, electric and mechanical heat generation in the motor 15 and the pumps 41 and 42 are increased. Therefore, electric and mechanical heat generation in those devices may contribute to heat the MCE element 12. The high rotating speed of the motor 15 in the initial operation condition obtains alternating flow of the heat transport medium with a frequency that is higher than that in the regular operation condition. Such flow heats the MCE element 12 by frictional heat.

According to this structure, the element temperature of the MCE element 12 can be changed to approach to the highly efficient temperature zone by using the thermo-magnetic cycle apparatus itself, without disposing the auxiliary apparatus 61 for auxiliary temperature control.

Tenth Embodiment

This embodiment is one of modifications based on a basic form provided by the preceding embodiment. In this embodiment, alternatively or additionally to the preceding embodiments, a temperature control on a part of the MCE element 12 is provided by cancelling or bypassing partially the flow of the heat transport medium to the MCE element 12.

As shown in FIG. 17, the MHP apparatus 11 has a bypass channel 1027 which allows flow of the heat transport medium to bypass a region of the low temperature end of the MCE element 12. An open-close valve 1028 which opens and closes the bypass channel 1027 is disposed in the bypass channel 1027. The bypass channel 1027 and the open-close valve 1028 provide a bypass device which enables flow of the heat transport medium bypasses a part of the MCE element 12. In this structure, the initial control part 1018 a adjusts the element temperature of the MCE element 12 by flowing the heat transport medium to bypass, i.e., to jump, a part of the MCE element 12 by the bypass device. According to this structure, the temperature of the MCE element 12 can be changed to approach to the highly efficient temperature zone by controlling the flow of the heat transport medium, without disposing the auxiliary apparatus 61 for auxiliary temperature control.

As shown in FIG. 18, this embodiment employs step 1073. An initial control is performed at step 1073. The initial control is provided by a bypass control which opens and closes the open-close valve 1028. The open-close valve 1028 is opened only in the initial control, and is closed in the regular control.

Other Embodiments

The present disclosure is not limited to the above embodiments, and the present disclosure may be practiced in various modified embodiments. The configuration, function, and advantages of the above described embodiments are just examples. The technical scope of the present disclosure shall not be limited by the above descriptions. The present disclosure is not limited to the above combination, and disclosed technical means can be practiced independently or in various combinations. Some extent of the disclosure may be shown by the scope of claim, and also includes the changes, which is equal to and within the same range of the scope of claim.

For example, means and functions of the control device 10 may be provided by only software, only hardware or a combination of the software and the hardware. For example, the control device may be made of an analogue circuit.

In the preceding embodiments, the multi-cylinder pump is provided by the swash plate type pump. Alternatively, the other type of displacement pump may be used. In the first embodiment, one work chamber is disposed to be associated with one cylinder of the pump. Alternatively, a plurality of cylinders and one work chamber may be disposed to be associated with, one cylinder and a plurality of work chambers may be disposed to be associated with, or a plurality of cylinders and a plurality of work chambers may be disposed to be associated with.

In the preceding embodiments, the present disclosure is applied to the air-conditioner for vehicle. Alternatively, the present disclosure may be applied to an air-conditioner for residences. Further alternatively, the present disclosure may be utilized to provide a hot-water-supply apparatus which heats water. In the embodiments, the MHP apparatus 11 uses the outside air as the main heat source. Alternatively, the other heat sources, such as water or soil, may be used as the main heat source.

In the preceding embodiments, the MHP apparatus 11 is shown as one example of the thermo-magnetic cycle apparatus. Alternatively, the present disclosure may be applied to a thermo-magnetic engine apparatus which is another one of the thermo-magnetic cycle apparatus. For example, a thermo-magnetic engine apparatus can be provided by adjusting the phase angle of the magnetic-field change and the heat transport medium flow on the MHP apparatus 11.

While the present disclosure has been described with reference to embodiments thereof, it is to be understood that the disclosure is not limited to the embodiments and constructions. The present disclosure is intended to cover various modification and equivalent arrangements. In addition, while the various combinations and configurations, are preferred, other combinations and configurations, including more, less or only a single element, are also within the spirit and scope of the present disclosure. 

What is claimed is:
 1. A thermo-magnetic cycle apparatus comprising: a magneto-caloric element which generates heat dissipation and heat absorption in response to strength change of an external magnetic field; a magnetic field modulating device which modulates an external magnetic field applied to the magneto-caloric element; a heat transporting device which flows heat transport medium for performing heat exchange with the magneto-caloric element so that a high temperature end and a low temperature end are generated on the magneto-caloric element; and a controller which controls the magnetic field modulating device and the heat transporting device, wherein the magneto-caloric element demonstrates high performance when an element temperature of the magneto-caloric element is in a highly efficient temperature zone, and wherein the controller comprises: an initial control part which adjusts the element temperature of the magneto-caloric element so that the element temperature approaches to the highly efficient temperature zone when the magneto-caloric element is in an initial state in which the element temperature is out of the highly efficient temperature zone; and a regular control part which controls the magnetic field modulating device and the heat transporting device after adjustment of the element temperature by the initial control part is performed.
 2. The thermo-magnetic cycle apparatus in claim 1, wherein the initial control part adjusts the element temperature of the magneto-caloric element so that at least a temperature of a part of the magneto-caloric element reaches to the highly efficient temperature zone.
 3. The thermo-magnetic cycle apparatus in claim 2, wherein the initial control part adjusts the element temperature of the magneto-caloric element so that a temperature on the high temperature end of the magneto-caloric element reaches to the highly efficient temperature zone.
 4. The thermo-magnetic cycle apparatus in claim 2, wherein the initial control part adjusts the element temperature of the magneto-caloric element so that a temperature on the low temperature end of the magneto-caloric element reaches to the highly efficient temperature zone.
 5. The thermo-magnetic cycle apparatus in claim 2, wherein the initial control part adjusts the element temperature of the magneto-caloric element so that a temperature on a middle temperature portion between the high temperature end and the low temperature end of the magneto-caloric element reaches to the highly efficient temperature zone.
 6. The thermo-magnetic cycle apparatus in claim 2, wherein the magnetic field modulating device has a permanent magnet which provides the external magnetic field, and wherein the initial control part adjusts the element temperature of the magneto-caloric element so that demagnetization of the permanent magnet is reduced.
 7. The thermo-magnetic cycle apparatus in claim 1, further comprising: a thermal device which uses temperature obtained on the low temperature end or the high temperature end; and an auxiliary apparatus, which is provided differently from the thermal device, and which adjusts the element temperature of a part or all of the magneto-caloric element, wherein the initial control part adjusts the element temperature by activating the auxiliary apparatus.
 8. The thermo-magnetic cycle apparatus in claim 7, wherein the auxiliary apparatus has a heater which heats the magneto-caloric element.
 9. The thermo-magnetic cycle apparatus in claim 7, wherein the auxiliary apparatus has a cooler which cools the magneto-caloric element.
 10. The thermo-magnetic cycle apparatus in claim 7, wherein the auxiliary apparatus has a thermal storage which stores the temperature obtained on the high temperature end or the low temperature end.
 11. The thermo-magnetic cycle apparatus in claim 1, further comprising: a heat exchange device which performs heat exchange between the auxiliary apparatus and the magneto-caloric element.
 12. The thermo-magnetic cycle apparatus in claim 11, wherein the heat exchange device includes a heat exchanger which performs heat exchange with the heat transport medium.
 13. The thermo-magnetic cycle apparatus in claim 12, wherein the heat exchanger is disposed on a member which defines a passage through which the heat transport medium flows or a member which accommodates the magneto-caloric element.
 14. The thermo-magnetic cycle apparatus in claim 11, wherein the thermal device includes a heat exchanger which performs heat exchange between a primary medium which is the heat transport medium and a secondary medium, and wherein the heat exchange device includes a heat exchanger which performs heat exchange with the secondary medium.
 15. The thermo-magnetic cycle apparatus in claim 12, wherein the thermal device includes a valve system which takes out a part of the heat transport medium, and wherein The heat exchanger includes a heat exchanger which performs heat exchange with the heat transport medium taken out via the valve system.
 16. The thermo-magnetic cycle apparatus in claim 2, wherein the initial control part controls the magnetic field modulating device and the heat transporting device to provide an initial operation condition which generates heat greater than that in the regular operation condition provided when the magnetic field modulating device and the heat transporting device are controlled by the regular control part.
 17. The thermo-magnetic cycle apparatus in claim 1, further comprising: a bypass device which provides flow of the heat transport medium so that the heat transport medium bypasses a part of the magneto-caloric element, wherein the initial control part adjusts the element temperature by flowing the heat transport medium so that the heat transport medium bypasses a part of the magneto-caloric element by the bypass device.
 18. The thermo-magnetic cycle apparatus in claim 1, wherein the highly efficient temperature zone is a temperature zone in which the magneto-caloric element can generate a predetermined temperature difference between the high temperature end and the low temperature end by overcoming a thermal load by using an own magneto-caloric effect.
 19. The thermo-magnetic cycle apparatus in claim 1, wherein the magneto-caloric element includes a plurality of element units which have different magneto-caloric effects.
 20. The thermo-magnetic cycle apparatus in claim 19, wherein the element units are arranged to place one element unit on a position closer to the high temperature end than the other element unit, the one element unit demonstrates a magneto-caloric effect at a temperature which is higher than a temperature where the other element unit demonstrates a magneto-caloric effect.
 21. A thermo-magnetic cycle apparatus comprising: a magneto-caloric element which generates heat dissipation and heat absorption in response to strength change of an external magnetic field; a magnetic field modulating device which modulates an external magnetic field applied to the magneto-caloric element; a heat transporting device which flows heat transport medium for performing heat exchange with the magneto-caloric element so that a high temperature end and a low temperature end are generated on the magneto-caloric element; and a controller which controls the magnetic field modulating device and the heat transporting device, wherein the controller comprises: an initial control part which adjusts a temperature of the magneto-caloric element so that a predetermined temperature difference is acquired between the high temperature end and the low temperature end; and a regular control part which controls the magnetic field modulating device and the heat transporting device after adjustment of the element temperature by the initial control part is performed.
 22. The thermo-magnetic cycle apparatus in claim 21, wherein the magneto-caloric element includes a plurality of element units which have different magneto-caloric effects.
 23. The thermo-magnetic cycle apparatus in claim 22, wherein the element units are arranged to place one element unit on a position closer to the high temperature end than the other element unit, the one element unit demonstrates a magneto-caloric effect at a temperature which is higher than a temperature where the other element unit demonstrates a magneto-caloric effect. 